The Trinamool Congress on Monday lost control of South Dinajpur zila parishad (district council) after its South Dinajpur district unit chief Biplab Mitra switched sides to join the Bharatiya Janata Party (BJP) along with 10 other members of the parishad, giving the party a majority in the council, which has 18 seats.South Dinajpur Zilla Parishad is the first district council in the state that has been taken over by the opposition party.Lipika Roy, chairperson of the parishad was among those who switched camp. Wilson Champramari, TMC MLA from Kalchini in Alipurduars district, also joined the BJP, taking the total number of TMC MLAs switching camp to five in the past one month.The defected members joined BJP in the presence of its national general secretary and Bengal in-charge Kailash Vijayvargiya, state unit chief Dilip Ghosh and national executive member Mukul Roy.“It’s a case of political earthquake for them (TMC) today. It is merely an extension of phase I (of getting TMC leaders to join BJP). By the time we complete the seventh phase, the Mamata Banerjee government will lose majority on the floor of the Assembly,” said Roy, who was the convenor of BJP’s Lok Sabha election management committee for Bengal and played a crucial role in getting aggrieved TMC leaders to leave the party.The last panchayat elections in Bengal took place in 2018, when the ruling TMC won all the 22 zilla parishads.The BJP wrested both South Dinajpur and Balurghat Lok Sabha seats from the TMC this year. Both these seats are in South Dinajpur district. While Biplab Mitra is credited with building the organisation of TMC in the district, he was aggrieved after party chief Mamata Banerjee removed him from the post district unit chief after sitting MP Arpita Ghosh lost to BJP’s Sukanta Majumdar.